Self centering pipe working machine

ABSTRACT

A self centering pipe-working machine has a circular frame portion positionable around a pipe section, an openable ring assembly in movable contact with the periphery of the frame portion, two pairs of clamping members attached to the frame portion on a first side thereof, and two pairs of clamping members attached to the frame portion on a second side thereof. Each of the first mentioned two pairs of clamping members are operably interconnected through universal joint means, and each pair of clamping members on the second side of the frame portion are operably connected to a corresponding pair of clamping members on the first side of the frame portion. Threaded means connects each pair of the first mentioned two pairs of clamping members to the universal joint means to provide the combined clamping and self centering adjustments. The other two pairs of clamping members on the other side of the frame correspond in unison to the first two pairs. Adjustable tool support means is removably attached to the openable ring member for rotative movement around a pipe section to be worked. In one embodiment, driving means is attached to the frame with the driving means having a driven wheel in contact with the rotatable ring assembly in order to rotate the tool support means around the pipe section. In another embodiment of the invention, the driving means includes a driven sprocket member in contact with a chainlike member secured to the periphery of the openable ring assembly in order to drive the ring assembly.

United States Patent Stunkard [451 Mai-.21, 1972 [54] SELF CENTERINGPIPE WORKING MACHINE [72] Inventor: Gerald A. Stunkard, P.O. Box 594,.lenks,

Okla. 74037 [22] Filed: Nov. 7, 1969 [21] Appl. No.: 874,758

Primary Examiner Leonidas Vlachos Att0rney-R0bert E. Massa 57 ABSTRACT Aself centering pipe-working machine has a circular frame portionpositionable around a pipe section, an openable ring assembly in movablecontact with the periphery of the frame portion, two pairs of clampingmembers attached to the frame portion on a first side thereof, and twopairs of clamping members attached to the frame portion on a second sidethereof. Each of the first mentioned two pairs of clamping members areoperably interconnected through universal joint means, and each pair ofclamping members on the second side of the frame portion are operablyconnected to a corresponding pair of clamping members on the first sideof the frame portion. Threaded means connects each pair of the firstmentioned two pairs of clamping members to the universal joint means toprovide the combined clamping and self centering adjustments. The othertwo pairs of clamping members on the other side of the frame correspondin unison to the first two pairs. Adjustable tool support means isremovably attached to the openable ring member for rotative movementaround a pipe section to be worked. In one embodiment, driving means isattached to the frame with the driving means having a driven wheel incontact with the rotatable ring assembly in order to rotate the toolsupport means around the pipe section. In another embodiment of theinvention, the driving means includes a driven sprocket member incontact with a chain-like member secured to the periphery of theopenable ring assembly in order to drive the ring assembly.

17 Claims, 7 Drawing Figures Patented March 21, 1972 3 Sheets-Sheet 1INVENTOR. GERALD A. STUNKARD m A TTORNEY mm N2 NQ Patented Marc h 21,1972 3,650,514

3 Sheets-Sheet 2 INVENTOR.

2- GERALD A. STUNKARD BY firm; 6 M,

ATTORNEY F a e.

A TTOR/VE Y BACKGROUND OF THE INVENTION This invention relates topipe-working machines. More particularly, this invention relates to selfcentering pipe working machines, and still more particularly, to selfcentering pipeworking machines usable for a variety of pipe-workingoperations, such as cutting, beveling, welding, grinding, drilling, orxraying.

Quite commonly, during pipe line operations, a pipe section must beworked. That is, the pipe section must be cut to a desired length, orthe end of a pipe section must be beveled to prepare it for a followingwelding operation, or the end of the pipe section must be speciallytreated as by grinding for some other special purpose. Pipe sections areusually provided in lengths of 40 feet and in diameters to 48 inches ormore depending upon the type of service to which the pipe will be subjected. Because of the cumbersome size of the pipe section, and becauseit cannot be ascertained in advance what operation must be provided foreach adjacent pipe section, the pipeworking operations are generallycarried on near the site where the pipe will be used. Therefore, it isdesirable to have a pipe-working apparatus which could be made portableand usable for either field or yard work, and which can be readilyadaptable to the particular operation desired to effect considerablesaving in time and labor.

A primary object of this invention is to provide a pipe-working machinewhich is efficient in operation, easy to use, and inexpensive tomanufacture.

Another object of this invention is to provide a pipe-working apparatuswhich is readily adaptable to various sizes of pipe.

Still another object of this invention is to provide a pipeworkingapparatus which is capable of performing a multiplicity of operations.

Another object of this invention is to provide a self-centeringpipe-working machine which is accurately positionable on a pipe.

Another object of this invention is to provide a self-centeringpipe-working machine which maybe easily and quickly positioned on apipe.

Still another object of this invention is to provide a self-centeringpipe-working machine which may be easily, quickly, and accuratelypositioned on a pipe section.

Still another object of this invention is to provide a pipeworkingmachine which may be accurately and efiiciently positioned on a pipesection and which is adaptable to receive various sizes of pipe.

Still another object of this invention is to provide a self-centeringpipe'working machine adaptable to support a working tool for peripheralmovement around a pipe.

Still another object of this invention is to provide a self-centeringpipe-working machine which is adaptable for either manual or poweredmovement of a pipe-working tool peripherally around a pipe.

BRIEF DESCRIPTION OF THE DRAWINGS Further objects and advantages of theinvention will become apparent from the following description and claimsand from the accompanying drawings wherein:

FIG. 1 is a side elevational view of a pipe-working machine according tothis invention.

FIG. 2 is a front elevational view of a pipe-working machine accordingto this invention along the lines 2-2 of FIG. 1.

FIG. 3 is a rear elevational view of a pipe-working machine according tothis invention along the lines 33 of FIG. 1.

FIG. 4 is a side elevational view of an alternate embodiment of apipe-working machine according to this invention similar to FIG. 1.

FIG. 5 is a sectional view along the lines 5-5 of FIG. 3.

FIG. 6 is a sectional view along the lines 6--6 ofFlG. 2.

FIG. 7 is a sectional view along the lines 7--7 of FIG. I.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A self-centering pipe-workingmachine according to this invention comprises a circular frame, anopenable ring assembly rotatable on the circular frame, self-centeringclamp means attached to the circular frame and clampable to a pipesection to be worked, the clamp means including a pair of clamp membersoperably connected through a universal joint, tool support meansconnected to the ring assembly, and means for rotating the ring assemblyon the frame.

An important feature of this invention is the capability of the clampmeans to center the device accurately as the clamping members engage thesurface of a pipe section so that the working tool, which may be acutting torch, grinding or polishing member, or other desired tool, willbe accurately positioned in relation to the portion of the pipe to beworked for orbital travel around the pipe. The clamping and centeringoperations of this machine are therefore easily and quicklyaccomplished.

Another important feature of this pipe working machine is the provisionof an openable ring assembly in conjunction with the self-centeringcapabilities of the clamp means.

The importance of these features can be best understood by reference toother devices which are known in the art. U.S. Pat. No. 2,146,959 toKugel, issued Feb. 14, 1939, describes a pipe cutter which includes aplurality of pipe-gripping members which position the pipeconcentrically in relation to a central opening of the device. However,as stated by the patentee, the device is put into operation by beingslipped over the end of the pipe and moved along to the point at whichthe operation is to take place, since the device is not adaptable tobeing opened for quick positioning directly around the position wherethe operation is to take place.

U.S. Pat. No. 2,086,764 to Brown, issued July 13, 1937, U.S. Pat. No.2,364,963 to Elliott, issued Dec. 12, 1944, and U.S. Pat. No. 2,687,880to Waterson, issued Aug. 31, 1954, each describe related apparatushaving an openable ring assembly permitting the ring assembly to bepositioned around a portion of a pipe section for carrying a workingdevice around the periphery of the pipe section. However, in each ofthese cases, the ring assembly, and therefore the working device, is notself-centering. In each of the foregoing instances, the means to adjustthe ring assembly concentrically with regard to the pipe section isindependently adjustable from the means to secure the apparatus to thepipe section.

Referring now to the drawings in detail, FIG. 1 describes a pipe-workingdevice 10, generally, according to this invention, is position upon asection of pipe 12 as it would be in holding a working tool in positionsuch as a cutting torch 14. Cutting torch 14 could be maintained inproper position for rotatable movement around the periphery of pipesection 12 for cutting a section of pipe to a desired length or forpreparing a beveled edge on the pipe section, of for presenting a smoothedge for the pipe section. Cutting torch 14 is shown in position forexample only, and it is understood that other working tools may be soheld in position, as for example a grinding tool, a drilling tool, orsome other special tool adaptable for rotatable movement around theperiphery of a pipe section. The pipe-working device includes a framemember 16 (shown more clearly in FIGS. 2 and 3), essentially circular inconformation and comprising a portion of a circle, and a two-componentopenable ring member 18, generally, comprised of first ring portion 20and second ring portion 22. Frame member 16 includes an annular groove24 as shown in FIG. 5, and ring member 20 includes a tongue portion 26adapted to move slidably and circumferentially in groove 24. Second ringportion 22 includes a tongue portion 28 which acts as a continuation oftongue 26 to move slidably in groove 24 as the openable ring 18 rotatesaround frame member 16 during operation of the device. Ring members 20and 22 can be machined accurately so that they will abut each otherprecisely permitting tongue portions 26 and 28 to operate smoothly ingroove 24.

FIG. 6 describes in detail how second ring portion 22 is hinged to firstring portion 20 by means of pin 30 positioned in bushing 32 which isplaced in opening 34 in first ring portion 20, and hinge plates 36 and38 which are secured to second ring portion 22 by means of machine bolts40 which pass through openings 42 in hinge plate 36 and openings 44 inring member 22, and are received threadably in threaded portions 46 ofhinge plate 38. Second ring portion 22 is received lockably in positionagainst first ring portion 20 by means ofa locking device formed byplate members 48 and 50, machine bolts 52 which pass through openings 54in plate member 48 and openings 56 in ring member 22 and are receivedthreadably in openings 58 in plate member 50, any by operation of athreaded bolt member 60 which has a threaded portion received ininterior threads of a nut member 62 fastened on plate 48, and whichpasses through opening 64 in plate 48 and opening 66 in ring member 20and which is received threadably in opening 68 in plate member 50. Thus,with ring member 22 in position abutting ring member 20, bolt member 60can be threaded into position to secure the alignment of ring members 20and 22. However, bolt member 60 can take a variety of arrangements,instead of being received threadably in opening 68, bolt member 60 couldjust as well pass through opening 68 and be received by a separatemachine nut threadable thereon, or bolt member 60 may be in the form ofapin member which is spring biased through openings 64, 66, and 68.Release of bolt member 60 from its locking position thus permits ringportion 22 to swing open on its hinge portion in order to permit theentire ring assembly 18 to be positioned around a pipe section forclamping of the pipe-working device thereon.

As shown most clearly in FIGS. 2 and 3, there are a plurality ofclamping arms 70, 72, 74, 76, 78, 80, 82, and 84. Clamping arms 70 and82 are positioned on shaft 86, clamping arms 72 and 84 are positioned onshaft 88, clamping arms 74 and 78 are positioned on shaft 90, andclamping arms 76 and 80 are positioned on shaft 92. Thus, clamping armspositioned on the same shaft are capable of moving in unison as theshaft rotates. As shown in shadow in FIG. 1, shaft is positionedrotatably in a bore 94 in frame member 16 which is coaxial with a bore96 in journal 98 which is integral with frame member 16. Shaft 92 issimilarly received rotatably in bore 100 of frame member 16 and bore 102in journal 98. Likewise, shafts 86 and 88 are received rotatably in asimilar bore through frame member 16 (not shown) and a bore through asimilar journal member (not shown). Each of the clamping arms includes ahardened tip 104 which may, if desired, be made adjustable in anysuitable manner so that each arm may contact a pipe sectionsimultaneously. Integral with each shaft 86, 88, 90, and 92, is anenlarged radial portion 106, 108, 110, and 112, respectively, with eachof said radial portions having thereon respectively, gear teeth 114,116, 118, and 120. Gear teeth 114 mesh with gear teeth 116 to causeshaft 88 to rotate in response to rotative movement of shaft 86, andgear teeth 118 mesh with gear teeth 120, to cause shaft 92 to rotate inresponse to rotative movement of shaft 90. Thus, the four clamping armssecured on shafts 86 and 88 rotate in unison, and the four clamping armssecured on shafts 90 and 92 rotate in unison.

The clamping members of this pipe-working device are arranged to workinterrelatedly as shown clearly in FIG. 3. A driving shaft 122 isarranged to rotate within journals 124 and 126 and secured to each endthereof universal joints 128 and 130. A left-hand feed screw 132 issecured to universal joint 128 by any suitable manner, as by a pin 133,and has a portion moveable bearably in journal 134 integral with frame135 and further has a cranking arm 136 secured to an extended portion138 thereof. A threaded member 140 has internal threads engaging thethreads ofleft-hand feed screw 132 and further has pins 142 and 143thereon to move slidably in slots 144 and 145 of yoke member 146 securedto extension 148 of arm 78 by suitable machine bolts 150. Similarly, aright-hand feed screw 152 has one end secured to universal joint 130 byany suitable manner, as by a pin 153, and has a portion moveablebearably in journal 154 integral with frame 155. Frames 135 and 155 aresecured to frame 16. A threaded member 156 has internal threads engagingthe threads of right-hand feed screw 152 and includes a pin 158 andanother pin, (not shown), (similar to pin 143), both of which moveslidably in slot 160 and another slot, (not shown), (similar to slot145), of yoke member 162 secured to extension 164 of arm 82 by means ofmachine bolts 166. Thus, turning of crank handle 136 causes rotation ofleft-hand feed screw 132 and right-hand feed screw 152 by reason oftheir interconnection through the universal joints and driving shaft tocause movement of members 140 and 156 along the feed screw members withconsequent slidable movement of pins 142 and 158 in the slots of yokemembers 146 and 162 so that clamping arms 78 and 82 are moved arcuately,and by further engagement of gear teeth 114, 116, 118, and 120, all ofthe clamping arms are moved simultaneously to contact the surface ofpipe section 12 and position the pipe-working device concentrically onthe pipe section. It is contemplated that left-hand screw 132, drivingshaft 122, and right-hand screw 152 could also be rotated by power meansas by being connected to an electric or hydraulic motor.

One means of adjustment of the operative members of this pipe-workingdevice are described in FIG. 7. Each of the threaded members 140 and 156include the adjustment means described by FIG. 7. Thus, threaded member140 has internal threads 168 which cooperate with external threads 170of adjustment member 172 which further has internal threads 174 whichcooperate with threads 176 on left-hand feed screw 132. Adjustmentmember 172 includes an under cut portion 178 against which aconventional Allen screw 180, received threadably in threaded bore 182,may be positioned. A similar adjustment means is incorporated intothreaded member 156 on right-hand screw 152. To bring about this fineadjustment, Allen screw 180 and a similar Allen screw in threaded member156 are loosened, a suitable spanner wrench is inserted in recesses 184and similar recesses in a like adjustment member in threaded member 156so that adjustment member 172 and the like adjustment member in threadedmember 156 may be moved in relation to screw members 132 or 152 andthreaded members 140 or 156, as necessary. Then, after the threadedmembers 140 and 156 have been adjusted as desired to secure the propersuitable fine adjustment, Allen screw 180 operating within member 140and the similar Allen screw within member 156 are tightened to securethis proper fine adjustment. Thus, a fine adjustment is provided foradjusting member 140 in relation to threaded member 132 or member 156 inrelation to threaded member 152.

As shown in FIG. 1, ring portions 20 and 22 are provided with grooves186 and 188 respectively, which provide means to guide a driving wheel190 having a peripheral surface of resilient material 192 along thelower surface of grooves 186 and 188 which, as in FIG. 1, may haveknurled surfaces 194 and 196, respectively, in order to have one meansof a friction drive for ring member 18. Resilient material 192 may be ofrubber, Nylon, Teflon, or other similar material which is slightlyresilient in order to provide a non-slipping driving means for the ringmember. It is preferable to have a resilient surface rather than thecooperation of two hard metallic surfaces on ring member 18 and drivingwheel 190, although metallic peripheries of ring 18 and wheel 190 couldbe utilized.

Driving wheel 190 is positioned on shaft 198 which is gearably connectedto transmission assembly 200 which is further driven by rotation ofshaft 202 and hand crank 204. Transmission assembly 200 may be ofconventional design and may be of a suitable gear ratio between shaft202 and 198 as may be most suitable for the particular purpose of theworking device. It is also contemplated that shaft 202 may be operablyconnected to a proper electric or hydraulic motor to provide the drivingforce. Transmission assembly 200 is secured to support frame 206 whichis attached to frame member 16. Thus, the driving force applied todriving wheel 190 permits rotation of ring member 18 around the pipesection to which the pipe-working device is clamped.

As shown in FIGS. 1 and 2, an adjustable tool support frame isattachable to ring member 18 and includes a support frame 208 havingslots 210 therein which receive set screws 212 which are furtherreceived threadably in first ring portion 20. Attached to support frame208 is a bar 214 upon which is adjustably positionable working toolclamp 216 which may be positioned longitudinally of bar 214 and securedangularly thereof by tightening of set screw 218 in clamp 216. FIG. 1shows a conventional cutting torch held in position on clamp 216although, as stated above, other types of working tools may be used.

FIG. 4 shows an alternate embodiment of a pipe working device accordingto this invention. In this embodiment a different means of driving ringassembly 18 is described. Instead of knurled surfaces 194 and 196 ingrooves 186 and 188, a chain member 220 is positioned in groove 186 anda similar chain member 222 is positioned in groove 188. Chain member 220is held in position by pin 224 passing through an end link of chain 220and through bore 226 adjacent the extremity of ring portion 20. Chain222 is held in position on ring portion 22 by means of pin 228 passingthrough an end link of chain 222 and further passing through bore 230 inring portion 22. Similar means of fastening the chain members areprovided for the other ends of chains 220 and 222. A sprocket 232 issecured to shaft 198 and has teeth 234 which engage the links of chains220 and 222 to provide the driving means for ring member 18 of thisembodiment. Chains 220 and 222 are so positioned on ring portions 20 and22 that no lost motion occurs in the engaging of sprocket teeth 234 asthey engage successively the individual chain portions 220 and 222.

In operation, threaded bolt member 60 is unscrewed to release secondring portion 22 from its position adjacent first ring portion 20, andtherefore the ring assembly 18 is opened and the pipe-working device ispositioned transversely of a pipe section with clamping arms 70, 72, 74,76, 78, 80, 82, and 84 initially outwardly rotated so that the pipesection may pass therebetween. Then, second ring portion 22 is broughtinto position adjacent ring portion 20 and threaded bolt member 60 istightened securely. Thus, a continuous smooth track or guiding surfaceis provided for the working tool which can be subsequently positioned onbar 214. With a pipe section brought between the clamping arms, crankhandle 136 is rotated causing clamping arms 70, 72, 74, 76, 78, 80, 82,and 84 to approach the pipe section and ultimately to contact the pipesection and clamp thereon securely. Because of the precise adjustmentcapabilities of this working device, as the device is clamped on thepipe section, the pipe section is securely held concentrically in regardto the circumference of ring assembly 18. A working tool, such ascutting torch 14, may then be positioned adjustably as desired in toolclamp 216. Operation of hand crank 204 then causes rotation of drivingwheel 190, and consequently rotation of ring member 18 with cuttingtorch 14 adjusted accurately, around the pipe section in a concentricmanner.

Since many different embodiments of this invention may be made withoutdeparting from the spirit and scope thereof, it is to be understood thatthe specific embodiments described in detail herein are not to be takenin a limiting sense, since the scope of the invention is best defined bythe appended claims.

Iclaim:

l. A pipe-working machine comprising:

a circular frame,

an openable ring assembly rotatable on said frame,

self-centering clamp means attached to said frame, said clamp meansincluding a pair of clamp members linkably connected thru a universaljoint, and said clamp means clampable to a pipe section to be worked,

tool support means connected to said ring assembly, and,

driving means for rotating said ring assembly on said frame.

2. A pipe-working machine as described in claim 1, wherein:

said clamp means includes a first pair of clamp members on a first sideof said frame and a second pair of clamp members on a second side ofsaid frame, and said first and second pair of clamp members are operablyinterconnected. 3. A pipe-working machine as described in claim 1,wherein:

at least one of said clamp members includes a pair of clamping armsgearably connected together for clamping operation in cooperation withthe other one of said clamp members. 4. A pipe-working machine asdescribed in claim 3, wherein:

at least one of said clamp members includes means for drivableconnection to said universal joint thru a screw member. 5. Apipe-working machine as described in claim 4, wherein:

said universal joint is connected to a rotatable driving member. 6. Apipe-working machine as described in claim 5, wherein:

said openable ring assembly is in tongue and groove relationship withthe periphery of said frame and includes means to lock said ringassembly on said frame. 7. A pipe-working machine as described in claim6, wherein:

said clamp means includes a first pair of clamp members on a first sideof said frame and a second pair of clamp members on a second side ofsaid frame, and said first and said second pair of clamp members areoperably interconnected. 8. A pipe-working machine as described in claim7, wherein:

said first pair of clamp members includes a first pair of clamping arms,said second pair of clamp members includes a second pair of clampingarms, and said first and second pairs of clamping arms are injuxtaposition on said first and second sides of said frame and areoperably interconnected. 9. A pipe-working machine as described in claim8, wherein:

said openable ring assembly includes a chain-like member secured to theperiphery thereof, and said driving means includes a gear assemblypositioned on said frame and said gear assembly further includes asprocket cooperating with said chain'like member to drive said ringassembly. 10. A pipe-working machine as described in claim 8, wherein:

said openable ring assembly is knurled around the periphery thereof, andsaid driving means includes a gear assembly positioned on said frame andsaid gear assembly further includes a wheel having a peripheral surfaceof resilient material positionable in driving contact with said ringassembly. 11. A pipe-working machine as described in claim 6, wherein:

said openable ring assembly includes a chain-like member secured to theperiphery thereof, and said driving means includes a gear assemblypositioned on said frame and said gear assembly further includes asprocket cooperating with said chain-like member to drive said ringassembly. 12. A pipe-working machine as described in claim 6, wherein:

said openable ring assembly in knurled around the periphery thereof, andsaid driving means includes a gear assembly positioned on said frame andsaid gear assembly further includes a wheel having a peripheral surfaceof resilient material positionable in driving contact with said ringassembly. 13. A pipe-working machine as described in claim 1, wherein:

said openable ring has a peripheral surface of resilient material, and

said driving means includes a gear assembly positioned on said frame andsaid gear assembly further includes a wheel having a knurled peripheralsurface positionable in driving contact with said ring. 14. Apipe-working machine as described in claim 6, wherein:

said openable ring has a peripheral surface of resilient material, andsaid driving means includes a gear assembly positioned on said frame andsaid gear assembly further includes a wheel having a knurled peripheralsurface positionable in driving contact with said ring. 15. Apipe-working machine as described in claim 8, wherein:

said openable ring has a peripheral surface of resilient material, andsaid driving means includes a gear assembly positioned on said frame andsaid gear assembly further includes a wheel having a knurled peripheralsurface positionable in driving contact with said ring.

16. In a pipe-working machine having a circular frame, and openable ringon said frame, means to clamp said machine to a pipe section, said meansincluding universal joint means; tool support means, and driving meansfor rotating said ring on said frame, the improvement wherein saidopenable ring is knurled around the periphery thereof, and said drivingmeans includes a wheel having a peripheral surface of resilient materialpositionable in driving contact with said ring.

17. In a pipe-working machine having a circular frame, an openable ringon said frame, means to clamp said machine to a pipe section, said meansincluding universal joint means; tool support means, and driving meansfor rotating said ring on said frame, the improvement wherein saidopenable ring has a peripheral surface of resilient material, and saiddriving means includes a wheel having a knurled peripheral surfacepositionable in driving contact with said ring.

1. A pipe-working machine comprising: a circular frame, an openable ringassembly rotatable on said frame, self-centering clamp means attached tosaid frame, said clamp means including a pair of clamp members linkablyconnected thru a universal joint, and said clamp means clampable to apipe section to be worked, tool support means connected to said ringassembly, and, driving means for rotating said ring assembly on saidframe.
 2. A pipe-working machine as described in claim 1, wherein: saidclamp means includes a first pair of clamp members on a first side ofsaid frame and a second pair of clamp members on a second side of saidframe, and said first and second pair of clamp members are operablyinterconnected.
 3. A pipe-working machine as described in claim 1,wherein: at least one of said clamp members includes a pair of clampingarms gearably connected together for clamping operation in cooperationwith the other one of said clamp members.
 4. A pipe-working machine asdescribed in claim 3, wherein: at least one of said clamp membersincludes means for drivable connection to said universal joint thru ascrew member.
 5. A pipe-working machine as described in claim 4,wherein: said universal joint is connected to a rotatable drivingmember.
 6. A pipe-working machine as described in claim 5, wherein: saidopenable ring assembly is in tongue and groove relationship with theperiphery of said frame and includes means to lock said ring assembly onsaid frame.
 7. A pipe-working machine as described in claim 6, wherein:said clamp means includes a first pair of clamp members on a first sideof said frame and a second pair of clamp members on a second side ofsaid frame, and said first and said second pair of clamp members areoperably interconnected.
 8. A pipe-working machine as describeD in claim7, wherein: said first pair of clamp members includes a first pair ofclamping arms, said second pair of clamp members includes a second pairof clamping arms, and said first and second pairs of clamping arms arein juxtaposition on said first and second sides of said frame and areoperably interconnected.
 9. A pipe-working machine as described in claim8, wherein: said openable ring assembly includes a chain-like membersecured to the periphery thereof, and said driving means includes a gearassembly positioned on said frame and said gear assembly furtherincludes a sprocket cooperating with said chain-like member to drivesaid ring assembly.
 10. A pipe-working machine as described in claim 8,wherein: said openable ring assembly is knurled around the peripherythereof, and said driving means includes a gear assembly positioned onsaid frame and said gear assembly further includes a wheel having aperipheral surface of resilient material positionable in driving contactwith said ring assembly.
 11. A pipe-working machine as described inclaim 6, wherein: said openable ring assembly includes a chain-likemember secured to the periphery thereof, and said driving means includesa gear assembly positioned on said frame and said gear assembly furtherincludes a sprocket cooperating with said chain-like member to drivesaid ring assembly.
 12. A pipe-working machine as described in claim 6,wherein: said openable ring assembly in knurled around the peripherythereof, and said driving means includes a gear assembly positioned onsaid frame and said gear assembly further includes a wheel having aperipheral surface of resilient material positionable in driving contactwith said ring assembly.
 13. A pipe-working machine as described inclaim 1, wherein: said openable ring has a peripheral surface ofresilient material, and said driving means includes a gear assemblypositioned on said frame and said gear assembly further includes a wheelhaving a knurled peripheral surface positionable in driving contact withsaid ring.
 14. A pipe-working machine as described in claim 6, wherein:said openable ring has a peripheral surface of resilient material, andsaid driving means includes a gear assembly positioned on said frame andsaid gear assembly further includes a wheel having a knurled peripheralsurface positionable in driving contact with said ring.
 15. Apipe-working machine as described in claim 8, wherein: said openablering has a peripheral surface of resilient material, and said drivingmeans includes a gear assembly positioned on said frame and said gearassembly further includes a wheel having a knurled peripheral surfacepositionable in driving contact with said ring.
 16. In a pipe-workingmachine having a circular frame, and openable ring on said frame, meansto clamp said machine to a pipe section, said means including universaljoint means; tool support means, and driving means for rotating saidring on said frame, the improvement wherein said openable ring isknurled around the periphery thereof, and said driving means includes awheel having a peripheral surface of resilient material positionable indriving contact with said ring.
 17. In a pipe-working machine having acircular frame, an openable ring on said frame, means to clamp saidmachine to a pipe section, said means including universal joint means;tool support means, and driving means for rotating said ring on saidframe, the improvement wherein said openable ring has a peripheralsurface of resilient material, and said driving means includes a wheelhaving a knurled peripheral surface positionable in driving contact withsaid ring.